Every Monday we will post an entry that hasn’t yet been published with a view towards harnessing the collective onomastic power of the internet. If you have any thoughts about the name’s origin, other variants it might be related to, other examples of its use, etc., please share them in the comments! If you wish to browse other Mystery Monday names, there is an index.

Today we’ve actually got TWO names, because we have a passing suspicion that one is the feminine form of the other. The first is Briant/Brient, which is found in France between the 12th and 14th centuries:
These French examples are from Paris and Chartres, both in the north, which makes it tempting to associated the name with Proto-Brythonic *brigonos, and to claim a Breton connection.

But if we take the possible feminine form — Brianda — the evidence for this name that we have makes the Breton connection seem less likely, for our examples of Brianda are from Italy and Spain, not France — this would be quite far south and west to find a Breton-influenced name:
Perhaps we’re wrong in connecting the two names. Perhaps we’re wrong about the origin of Briant. Do you have any thoughts? Any French examples of Brianda? Please share in the comments!

Brient is definitely a Breton masculine name; see, for instance, J. Loth, Chrestomatie Bretonne (Armoricain, Gallois, Cornique), Première Partie, Breton – Armoricain, Paris, 1890, p. 111. This is also apparent from a weath of examples in both English and French documents that can be found by searching on “brientius” “brientii”. It produced a variety of French patronymic surnames, including Briand, Briant, and Briend, according to Dauzat, Dictionnaire étymologique des noms et prénoms de France s.nn. Briand, Briend.

According to Gary D. German, <a href="www.wales.ac.uk/Resources/Documents/Research/BretonPatronymsBritishHeroicAge.pdf"Breton Patronyms and the British Heroic Age [PDF], Old Breton brient is ‘free man; privilege’, cognate with Middle Welsh breint ‘privilege’, to which Kenneth Jackson, Language and History in Early Britain, p. 447, adds late Old Welsh bryeint; the modern Welsh is braint ‘privilege’. (Other bits and pieces found online lead me to think that German may have failed to distinguish OBret brient ‘privilege’ from OBret brientin ‘free man’.)

The feminine Brianda is almost certainly a different name, but beyond that I’ve no ideas as yet.

The earliest instance of Brianda that I can find is Brianda uxor Guillelmi de Bello 1250, Nr. 845 in Dominico Carutti,Regesta comitum Sabaudiae, marchionum in Italia ab ultima stirpis origine ad an. MDCCLIII, 1889. Her husband’s name is given more fully as Guillelmus de Bello Videre elsewhere in the document. (I might add that the masculine counterpart, Briandus, appears in 1282 as the name of a witness to Nr. 530,) Guillelmus held the castrum de Falaverio; this is now the Château de Fallavier, and Guillelmus is called Guillaume de Beauvoir in modern French sources. From Corpus des inscriptions de la France médiévale 15: La ville de Viennes en Dauphiné, p. 90:

The name was also borne in the mid-14th century by Brianda de Got (d’Agou(l)t, de Agou(l)t), the mother of Maria de Luna and wife of Lope, Conde de Luna; she was from Provence. Maria’s younger sister was also named Brianda.

A little earlier, in 1323, we have a Brianda, described as the sister of Guillelmus Artaudi marrying Petrus de Osia, according to K.H. Schäfer, Die Ausgaben der Apostolischen Kammer unter Johann XXII.: Nebst den Jahresbilanzen von 1316–1375, 1911, p. 84. Petrus was the brother of Pope John XXII; in modern French his name appears in a variety of forms, but French Wikipedia uses Pierre Duèze. It also gives his (third) wife’s name as Béraude, not Brianda, but I’ve not found a source for this, and Stefan Weiß, Versorgung des päpstlichen Hofes in Avignon mit Lebensmitteln (1316-1378): Studien zur Sozial- und Wirtschaftsgeschichte eines mittelalterlichen Hofes, 2002, p. 288, follows Schäfer.

We also find the masculine form: Iean le Lievre, Histoire de l’Antiquité et Saincteté de la Cité de Vienne en la Gaule Celtique, 1623, Ch. XLIX, deals with Briandus de l’Agnieu, archbishop of Vienne in the early 14th century. From what is visible of Édouard Perroy, Les familles nobles du Forez au XIIIe siècle: essais de filiation, Volume 20, at Google Books it is clear that the name Briand(us) was in use in that family at least from 1134 and in other families as well.

All of these examples, as well as a few later ones that I noted in passing, are from Occitania and northern Spain. It is entirely conceivable that Briand(us) and Brianda go back to a Gaulish or Celtiberian name cognate with the Breton name. I don’t see a plausible Germanic or Romance source, but I also don’t know whether there are any known Continental Celtic survivals in this area. Note that the feminine name could be younger than the masculine: the relatively early appearance of feminine Brianda could be the result of Romance influence. In Brittany that influence would have been later and weaker. (I did in fact find Brianda 1570 and Briande 1576, among other instances, in the baptismal records of Cancale, in Brittany, so it appears that the masculine Breton name was eventually feminized under French influence.